Set unchangeable some part of editText android

问题:

I have some EditText for mobile number input. App must add unique text for every country. For example for Armenia is must add +374 , and user must fill other numbers. Also +374 must be unchangeable, user can't change or remove it. So is there some kind of ways for doing this?

EDIT:

I don't want to use textView or another view with this text and put it left of the ediText. I want to find some way with less operations. I need text to be frozen not to check every text changes or add missing text when user will delete some part of it.

回答1:

Create a custom drawable class that will help to convert text into drawable.

public class TextDrawable extends Drawable {

private final String text;
private final Paint paint;

public TextDrawable(String text) {
    this.text = text;
    this.paint = new Paint();
    paint.setColor(Color.BLACK);
    paint.setTextSize(16f);
    paint.setAntiAlias(true);
    paint.setTextAlign(Paint.Align.LEFT);
}

@Override
public void draw(Canvas canvas) {
    canvas.drawText(text, 0, 6, paint);
}

@Override
public void setAlpha(int alpha) {
    paint.setAlpha(alpha);
}

@Override
public void setColorFilter(ColorFilter cf) {
    paint.setColorFilter(cf);
}

@Override
public int getOpacity() {
    return PixelFormat.TRANSLUCENT;
}
}

Then set the drawable to left of the edittext as

EditText et = (EditText)findViewById(R.id.editText1);
String code = "+374";
et.setCompoundDrawablesWithIntrinsicBounds(new TextDrawable(code), null, null, null);
et.setCompoundDrawablePadding(code.length()*10);

Where the edittext is defined in the layout file as

<EditText
android:id="@+id/editText1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="16sp"
android:ems="10" >
  <requestFocus />
</EditText>

Final Output looks like

回答2:

public class MainActivity extends Activity {

private EditText editText;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    editText = (EditText) findViewById(R.id.editText1);
    editText.setText("+374");
    Selection.setSelection(editText.getText(), editText.getText().length());
    editText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
            // TODO Auto-generated method stub

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
            if (!s.toString().startsWith("+374")) {
                editText.setText("+374");
                Selection.setSelection(editText.getText(), editText
                        .getText().length());

            }

        }

    });
}

}

回答3:

Use Text watcher and when user enters +3 it completes with +374 and it compares the first four characters and if it is same disable the back press of the softkeyboard so that it will not change the text and enters the other digit which append for the text used from the textwatcher

回答4:

you can create class extend AppCompatEditText or EditText.

public class CEditTextMaster extends AppCompatEditText {

        private boolean isNeedNoChangeSomeCharacters;
        private String charactersNoChange;

        public CEditTextMaster(Context context) {
            super(context);
            init(context, null);
        }

        public CEditTextMaster(Context context, AttributeSet attrs) {
            super(context, attrs);
            init(context, attrs);
        }

        public CEditTextMaster(Context context, AttributeSet attrs, int defStyleAttr) {
            super(context, attrs, defStyleAttr);
            init(context, attrs);
        }

        public void init(Context context, @Nullable AttributeSet attrs) {

            if (isInEditMode())
                return;

            addTextChangedListener(new TextWatcher() {
                @Override
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {

                }

                @Override
                public void onTextChanged(CharSequence s, int start, int before, int count) {

                }

                @Override
                public void afterTextChanged(Editable s) {
                    if (isNeedNoChangeSomeCharacters && charactersNoChange != null) {
                        if (!getText().toString().startsWith(charactersNoChange)) {
                            removeTextChangedListener(this);
                            if (charactersNoChange.length() > s.length()) {
                                setText(charactersNoChange);
                            } else {
                                setText(charactersNoChange + getText());
                            }
                            setSelection(getText().toString().length());
                            addTextChangedListener(this);
                        }
                    }
                }
            });

        }

        @Override
        protected void onSelectionChanged(int selStart, int selEnd) {
            if (isNeedNoChangeSomeCharacters && charactersNoChange != null) {
                if (length() > charactersNoChange.length() && selStart < charactersNoChange.length()) {
                    setSelection(charactersNoChange.length(),selEnd);
                }
            }
        }


        @Override
        public void setText(CharSequence text, BufferType type) {
            super.setText(text, type);
            if (isNeedNoChangeSomeCharacters && charactersNoChange != null) {
                if (!getText().toString().trim().startsWith(charactersNoChange)) {
                    setText(charactersNoChange + getText());
                }
            }
        }

        public void setCharactersNoChangeInitial(String charactersNoChange) {
            isNeedNoChangeSomeCharacters = true;
            this.charactersNoChange = charactersNoChange;
            if (!getText().toString().trim().startsWith(charactersNoChange)) {
                setText(getText());
            }
        }

}

for use:

edt.setCharactersNoChangeInitial("+734 ");